含氦泡辐照老化材料层裂损伤计算方法分析  

Simulation method of spall damage for self-radiation damage aging materials with helium bubbles

作　　者：张凤国[1] 刘军[1] 王言金[1] 王裴[1] 郑晖[1] ZHANG Fengguo;LIU Jun;WANG Yanjin;WANG Pei;ZHENG Hui(Institute of Applied Physics and Computational Mathematics,Beijing 100094,China)

机构地区：[1]北京应用物理与计算数学研究所,北京100094

出　　处：《爆炸与冲击》2023年第10期87-93,共7页Explosion and Shock Waves

基　　金：国家自然科学基金项目(12271054,12172063);科学挑战专题(TZ2018001)。

摘　　要：辐照条件下,一些材料内部产生大量的氦泡等微缺陷,氦泡的大小和数密度随着辐照年限的增长而增长。氦泡分布特征的变化不仅影响材料本身的物理、力学性质,而且直接影响材料层裂损伤演化后期材料破坏颗粒度的分布特征。延性材料的层裂损伤演化过程一般包括孔洞的成核、增长和汇合,但因已有孔洞对新成核孔洞存在抑制作用,当初始孔洞数密度达到一定临界值时,材料内部没有新的孔洞成核,因此,层裂损伤的计算可以不考虑新孔洞成核的影响。本文中基于损伤早期演化的特征,给出了这一临界值的计算方法,并进一步探讨了含氦泡辐照老化钚材料层裂损伤的计算方法。同时,在完善孔洞增长(void growth,VG)层裂损伤模型中参数的确定方法的基础上,借助含氦泡常规铝材料的层裂实验结果,对此问题进行了定性的分析:在氦泡尺寸变化不大的情况下,当氦泡浓度低于临界氦泡浓度时,需要考虑初始氦泡以及新增孔洞的综合影响;反之,可以采用简单的层裂损伤模型,不需要计算孔洞成核,但由于增长孔洞之间的相互影响,损伤模型的初始损伤参数需要重新确定。Under irradiation conditions,a large number of micro-defects such as helium bubbles are produced in some materials,and the size and number density of helium bubbles increase with the increase of irradiation years.The variation of helium bubble distribution not only affects the physical and mechanical properties of the material itself,but also directly affects the distribution characteristics of fracture particle size in the later stage of spallation damage evolution.The evolution process of spallation damage in ductile materials generally includes nucleation,growth and confluence of pores.However,due to the inhibition of existing pores on new nucleation pores,when the initial number density of pores reaches a certain critical value,the calculation of spallation damage may not consider the influence of new nucleation.Based on the characteristics of early damage evolution,a formula for calculating this critical value is given,and based on this formula,the calculation method of spallation damage of plutonium materials irradiated by helium bubbles is further discussed.Then,in view of the difference between the initial damage parameters of the damage model and the real initial damage of the material,we propose a method to determine the damage parameters in the void growth(VG)model.Finally,this problem is analyzed qualitatively by using the experimental results of spallation of conventional aluminum materials containing helium bubbles.The analysis results show that for the calculation of spallation damage of irradiated materials containing helium bubbles,only when the helium bubble size changes little and the helium bubble concentration is lower than the critical helium bubble concentration given in this paper,it is necessary to consider the comprehensive influence of initial helium bubbles and new holes.otherwise,a simple spallation damage model can be adopted,and the nucleation of holes does not need to be calculated.

关 键 词：氦泡 层裂损伤 辐照老化 临界氦泡浓度 

分 类 号：O346.1[理学—固体力学]